This BBC review seems to sum it up nicely:
It's hard to describe Shane Meadows' latest film without making it appear a great deal less interesting than it actually is. It's a semi-autobiographical tale of a young boy adopted by a gang of skinheads in a grey seaside town. And on that basis, This Is England sounds, in short, like typical grimesville British filmmaking - concrete, rain and misery. This couldn't be further from the truth. In fact, the film is fizzing with energy and humour, powered by brilliantly engaging performances.
Chief among these is newcomer Thomas Turgoose as Sean, a put-upon 12-year old who finds unexpected friendship with a group of local skinheads led by the sweet natured Woody (Joseph Gilgun, another stand-out performance). These skins are a far cry from the image of racist thuggery that the movement became known for in the 80s. It's all about the music, and of course the clothes - although Sean is too small for Doc Marten boots, he still gets the haircut, the plaid shirt and the braces. For a while, everything is sweet in Sean's world. He even shares his first kiss with a Boy George lookalike with the charming name of Smell.
But soon, conflict arrives in the form of Combo (Stephen Graham, also superb), an old mate of the gang whose time in prison has left him with a strong sympathy for the National Front. Combo's racist agenda splits the gang and Sean, tragically, finds himself turning to Combo as a substitute for the father he lost in the Falklands. Meadows is an exhilarating filmmaker and This Is England is his best film to date - an honest, emotional, funny and deeply moving portrait of growing up. Don't miss it.